Knowledge of the solubility of gases in water and other fluids is of importance in understanding many biological processes. In particular, the high precision (to plus or minus 0.02%) solubility of simple hydrocarbon gases like CH4, C2H6, and C2H4, C2H2, and C3H8 in pure water over a range of temperatures (0 to 60 degrees C at atmospheric pressure) will be useful for the understanding of hydrophobic interaction. The high precision and wide temperature range are needed in order to obtain precise values for the changes of the thermodynamic functions (Gibbs energy, entropy, enthalpy, and especially heat capacity) on solution. Scaled particle theory and the theories of A. Ben-Naim, on hydrophobic interactions will be used for interpretation. A new flow apparatus for determining the solubility of gases in small quantities of solvents and solutions will be built. This apparatus has the capability of being automated, of making many rapid measurements, of studying temperature and pressure dependence of solubilities, and even determining non-equilibrium solubilities by differnce (albeit with poorer precision). After standardization and completion, it will be used to study the solubility of atmospheric gases and other gases in a variety of liquids and solutions. Finally, the partial molar volume of gases will be determined in water, aromatic and aliphatic organic solvents, and model liquids for cell membranes like olive oil and isobutanol.